In a report on the rollout of the COVID-19 vaccine programme, the House of Commons public accounts committee highlighted that almost 3m people remained unvaccinated at the end of May this year, which put them at greater risk of being hospitalised or dying if they contracted the virus.
A further 1.5m have only had one dose of the vaccine and, in those over 18, uptake of booster jabs has only reached 73% of the 32.6m people eligible.
The committee recommended that to increase uptake the vaccine programme should 'set itself a challenge to reduce the overall number of adults who are unvaccinated to 2.5m, and achieve an 80% uptake for first boosters among adults, within four months of announcing the challenge'.
The report also highlighted that low vaccination uptake had persisted in many vulnerable groups, including some ethinic groups, pregnant women and those with learning disabilities, and that uptake among those under 18 was also low.
Gaps in uptake widened further when boosters were taken into account. Compared with people of white British origin, people of black, black British and Pakistani origins were less than half as likely to have had their boosters, the report said.
It pointed out that while the committee was hearing evidence earlier this year, NHS England had described targeted approaches aimed at increasing uptake, however 'it was still not really clear to us that officials knew which approaches had been most successful, nor that they had a clear plan to address pockets of low uptake in future'.
The committee called on NHS England and the UK Health Security Agency (UKHSA) to 'urgently evaluate' measures that increase uptake and develop 'fresh approaches to tackling the persistent low uptake observed in some ethnic groups'.
The report said that the vaccination programme had been a huge success and recommended the DHSC apply the lessons learned from the roll out to other screening and vaccination programmes.
However, it added: 'The nature of the pandemic and the health response to it are changing, and the programme must not allow these first stage achievements to cloud the need to review and adapt its approaches.'
The report said that because the country was no longer in a 'state of emergency and other issues have eclipsed COVID-19 in the news, vaccination is now worryingly a lower priority for many people'.
The committee also raised concerns that lack of staff to administer vaccines and NHS England plans to cut the number of vaccination sites could hamper the programme and possibly reduce uptake in future.
It said: 'Our own recent report looking at NHS backlogs and waiting times highlighted the particular strains on the GP workforce, who have delivered around half of all COVID-19 vaccinations to date. It will be a considerable challenge to maintain convenience and accessibility to COVID-19 vaccinations while giving staff the chance to recharge and return to their normal, equally important, roles.'
The report said that the vaccine programme had spent £5.6bn by October 2021, highlighting that this was significantly less than the £13.5bn spent on NHS Test and Trace and £15bn spent on PPE by the DHSC during 2020/21.
Public accounts committee chair Dame Meg Hillier said: 'The DHSC and NHS England must build on the initial successes of the vaccine programme and redouble efforts to reach people who are unvaccinated and at greater risk of becoming hospitalised or dying as a result of COVID-19.
'The committee recognises the enormous effort by those who developed, secured and administered our COVID vaccines. The vaccine programme made a real difference. As well as saving lives it has reduced the ongoing impact of the pandemic.
'It’s important that the early success does not mean that the DHSC and NHS England take their eye off the ball in tackling future challenges and getting vaccines to hard to reach groups.'
Practices have been given until 14 July to sign up to take part in the autumn COVID-19 booster campaign. The autumn boosters are currently expected to cover patients in care homes for older people, health and care workers, those aged over 65 and patients aged 16-65 in at-risk groups.
A report by the National Audit Office on the COVID-19 vaccine roll-out earlier this year found GP-led sites were the most cost-effective and popular part of the vaccination programme.